Behenamidopropyl dimethylamine/behenic acid (sold under the tradename Catemol® 220-B and available from Phoenix Chemical, Inc., Somerville, N.J.) can be classified as a cationic organic salt with a small amount of free behenic acid. Trade literature for this material describes its solubility in a variety of oils at elevated temperature and its ability to dissolve heated cyclomethicone (for example, 65–70 degrees C.) and then to form an opaque gel upon cooling with a smooth emollient feel. For water/oil systems such as makeup it reduces the shiny, oily appearance on the skin.
In general, soft solids are gelled or made more solid using triglycerides, clays or silicone elastomers.
U.S. Pat. No. 5,019,375 to Tanner et al describes low residue, high viscosity antiperspirant creams comprising a volatile silicone, a particulate antiperspirant, a clay thickening agent, and a non-volatile paraffinic hydrocarbon fluid.
U.S. Pat. No. 4,526,780 to Marschner et al describes anhydrous antiperspirant paste or cream compositions comprising an oil absorbent material homogeneously dispersed in a vehicle comprising 25–55% of a volatile silicone and a clay suspending/thickening agent in the form of a gel.
U.S. Pat. No. 5,225,188 to Abrutyn et al describes underarm products comprising volatile and/or non-volatile alkylmethylsiloxanes.
U.S. Pat. No. 5,718,890 to Putnam et al describes antiperspirant cream compositions comprising selected triglyceride gellants.
U.S. Ser. No. 10/267,544 filed Oct. 9, 2002 describes a low residue antiperspirant and/or deodorant composition in the form of an anhydrous, surfactant-free and antiseptic alcohol-free suspension exhibiting a syneresis of less than 8% and comprising: a volatile silicone; a selected silicone elastomer, an antiperspirant active; and polyethylene beads having a particle size in the range of 5–40 microns and a density in the range of 0.91–0.98 g/cm3.
Other references related to soft solid formulations include:
(a) particulate thickening agents such as fumed silica: for example, U.S. Pat. No. 5,069,897 to Orr; and U.S. Pat. No. 4,937,069 to Shin; and
(c) selected volatile and/or non-volatile alkylmethylsiloxanes such as those including a structuring wax: for example, PCT applications WO 97/16161 and 16162 both of which are assigned to Unilever PLC.
The use of a class of compositions known as silicone elastomers in cosmetic compositions has shown some interesting results. PCT case WO 97/44010 and assigned to the same assignee as this application describes a silicone gel material made by combining (a) a volatile silicone material and (b) an organopolysiloxane material (or silicone elastomer) as a gelling agent wherein the organopolysiloxane material (silicone elastomer) can be a reaction product of a vinyl-terminated siloxane polymer and a silicon hydride cross-linking agent. Related technology is also disclosed in PCT publications WO 98/00097, WO 98/00104 and 98/00105 assigned to Unilever PLC on cross-linked non-emulsifying elastomers.
U.S. Pat. No. 5,599,533 to Stepniewski et al assigned to Estee Lauder describes a stable water-in-oil emulsion system formed with an organopolysiloxane elastomer, a vehicle in which the elastomer is dispersed or dispersible, a stabilizing agent, a surfactant and an aqueous component. A commercial product known as “REVELATION” retexturizing complex for hands and chest sold by the same assignee contains a silicone gel material with an organopolysiloxane component and octamethylcyclotetrasiloxane.
EP 0 787 758 A1 teaches a method for solvent thickening by using a silicone latex having a plurality of crosslinked polysiloxane particles.
Another recent case assigned to the same assignee as this application is PCT Publication WO 99/51192 and U.S. patent application Ser. No. 9/273,152 which describes antiperspirant compositions with the use of broad categories of elastomers. Other examples of the use of elastomer type materials and/or methods for processing such materials may be found in PCT Publications WO 98/00097; WO 98/00104; WO 98/00105; WO 98/18438; WO 98/42307 all of which are incorporated herein by reference as to elastomer materials and methods of processing such materials.
Two major problems have been observed when the use of elastomer materials is included in soft solid formulations. The first problem is reduction in efficacy due to the formation of an occlusive elastomeric film which prevents the active from diffusing into the sweat duct. The second problem is the consistency of the product as evidenced by high viscosity and elastic behavior when applied to the surface of the skin.
Thus, it is an object of the invention to provide improved cosmetic compositions with reduced syneresis. It is a further object to provide soft solid antiperspirant/deodorant products that have low residue, especially on clothing. It is yet another object to provide a soft solid that is made with gelled cyclomethicone and cationic organic salts. These and other objects of the invention will be apparent from the following description of the invention.